Related papers: Primordial black holes and asteroid danger
Microscopic black holes explode with their temperature varying inversely as their mass. Such explosions would lead to the highest temperatures in the present universe, all the way to the Planck energy. The possibility that a…
A universal mechanism may be responsible for several unresolved cosmic conundra. The sudden drop in the pressure of relativistic matter at $W^{\pm}/Z^{0}$ decoupling, the quark--hadron transition and $e^{+}e^{-}$ annihilation enhances the…
Primordial black holes (PBHs) are a compelling dark matter candidate and a unique probe of small-scale cosmological fluctuations. Their formation is usually attributed to large positive curvature perturbations, which collapse upon Hubble…
I briefly outline recent theoretical developments on the formation of the first massive black holes (MBHs) that may grow into the population of MBHs powering quasars and inhabiting galactic centers today. I also touch upon possible…
A perturbative analysis shows that black holes do not remember the value of the scalar field $\phi$ at the time they formed if $\phi$ changes in tensor-scalar cosmology. Moreover, even when the black hole mass in the Einstein frame is…
Primordial black holes (PBHs) are theoretical black holes which may be formed during the radiation dominant era and, basically, caused by the gravitational collapse of radiational overdensities. It has been well known that in the context of…
It is possible that a multi-component dark matter model is required if primordial black holes only contribute to a fraction of the energy density in dark matter. This is increasingly more likely with respect to the case of $f_{\rm PBH} =…
We conduct an analysis of a $U(1)_{B-L}$ extended inert doublet model and obtained the parameter space allowing strong first order phase transitions. We show that a large part of the parameter space can cause double first-order phase…
Primordial black holes (PBHs) could provide the dark matter but a variety of constraints restrict the possible mass windows to $10^{16} - 10^{17}$g, $10^{20} - 10^{24}$g and $10 - 10^3M_{\odot}$. The last possibility is of special interest…
Observation of an exploding black hole would provide the first direct evidence of primordial black holes, the first direct evidence of Hawking radiation, and definitive information on the particles present in nature. However, indirect…
The possibility that primordial black holes (PBHs) are the dark matter (or a fraction thereof) has attracted much attention recently. Their spatial clustering is a fundamental property which determines, among others, whether current…
We review the role of primordial black holes (PBHs) for illuminating the dark ages of the cosmological evolution and as dark matter (DM) candidates. We elucidate the role of phase transitions for primordial black hole formation in the early…
The idea of dark matter in the form of primordial black holes has seen a recent revival triggered by the LIGO detection of gravitational waves from binary black hole mergers. In this context, it has been argued that a large initial…
We consider the role of secondary infall and accretion onto an initially overdense perturbation in matter-dominated eras, like the one which is likely to follow the end of inflation. We show that primordial black holes may form through…
Primordial black holes (PBHs) may have formed through the gravitational collapse of cosmological perturbations that were generated and stretched during the inflationary era, later entering the cosmological horizon during the decelerating…
While large numbers of supermassive black holes have been detected at z>6, their origin is still essentially unclear. Numerical simulations have shown that the conditions for the classical direct collapse scenario are very restrictive and…
Observations of protoplanetary disks with high angular resolution using an ALMA interferometer showed that ring-shaped structures are often visible in their images, indicating strong disturbances in the disks. The mechanisms of their…
We have studied the evolution of primordial black holes (PBHs) in a universe with a variable gravitational constant and bulk viscosity. We have found that the strength of gravity has changed appreciably in the early universe. The…
Primordial black holes (PBHs) may form in the early universe when pre-existing adiabatic density fluctuations enter into the cosmological horizon and recollapse. It has been suggested that PBH formation may be facilitated when fluctuations…
The black holes detected by current and future interferometers can have diverse origins. Their expected mass and spin distributions depend on the specifics of the formation mechanisms. When a physically motivated prior distribution is used…